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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.calculator2;
import androidx.recyclerview.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
/**
* Adapter for RecyclerView of HistoryItems.
*/
public class HistoryAdapter extends RecyclerView.Adapter<HistoryAdapter.ViewHolder> {
private static final String TAG = "HistoryAdapter";
private static final int EMPTY_VIEW_TYPE = 0;
public static final int HISTORY_VIEW_TYPE = 1;
private Evaluator mEvaluator;
private final Calendar mCalendar = Calendar.getInstance();
private List<HistoryItem> mDataSet;
private boolean mIsResultLayout;
private boolean mIsOneLine;
private boolean mIsDisplayEmpty;
public HistoryAdapter(ArrayList<HistoryItem> dataSet) {
mDataSet = dataSet;
setHasStableIds(true);
}
@Override
public HistoryAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final View v;
if (viewType == HISTORY_VIEW_TYPE) {
v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.history_item, parent, false);
} else {
v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.empty_history_view, parent, false);
}
return new ViewHolder(v, viewType);
}
@Override
public void onBindViewHolder(final HistoryAdapter.ViewHolder holder, int position) {
final HistoryItem item = getItem(position);
if (item.isEmptyView()) {
return;
}
holder.mFormula.setText(item.getFormula());
// Note: HistoryItems that are not the current expression will always have interesting ops.
holder.mResult.setEvaluator(mEvaluator, item.getEvaluatorIndex());
if (item.getEvaluatorIndex() == Evaluator.HISTORY_MAIN_INDEX) {
holder.mDate.setText(R.string.title_current_expression);
holder.mResult.setVisibility(mIsOneLine ? View.GONE : View.VISIBLE);
} else {
// If the previous item occurred on the same date, the current item does not need
// a date header.
if (shouldShowHeader(position, item)) {
holder.mDate.setText(item.getDateString());
// Special case -- very first item should not have a divider above it.
holder.mDivider.setVisibility(position == getItemCount() - 1
? View.GONE : View.VISIBLE);
} else {
holder.mDate.setVisibility(View.GONE);
holder.mDivider.setVisibility(View.INVISIBLE);
}
}
}
@Override
public void onViewRecycled(ViewHolder holder) {
if (holder.getItemViewType() == EMPTY_VIEW_TYPE) {
return;
}
mEvaluator.cancel(holder.getItemId(), true);
holder.mDate.setVisibility(View.VISIBLE);
holder.mDivider.setVisibility(View.VISIBLE);
holder.mDate.setText(null);
holder.mFormula.setText(null);
holder.mResult.setText(null);
super.onViewRecycled(holder);
}
@Override
public long getItemId(int position) {
return getItem(position).getEvaluatorIndex();
}
@Override
public int getItemViewType(int position) {
return getItem(position).isEmptyView() ? EMPTY_VIEW_TYPE : HISTORY_VIEW_TYPE;
}
@Override
public int getItemCount() {
return mDataSet.size();
}
public void setDataSet(ArrayList<HistoryItem> dataSet) {
mDataSet = dataSet;
}
public void setIsResultLayout(boolean isResult) {
mIsResultLayout = isResult;
}
public void setIsOneLine(boolean isOneLine) {
mIsOneLine = isOneLine;
}
public void setIsDisplayEmpty(boolean isDisplayEmpty) {
mIsDisplayEmpty = isDisplayEmpty;
}
public void setEvaluator(Evaluator evaluator) {
mEvaluator = evaluator;
}
private int getEvaluatorIndex(int position) {
if (mIsDisplayEmpty || mIsResultLayout) {
return (int) (mEvaluator.getMaxIndex() - position);
} else {
// Account for the additional "Current Expression" with the +1.
return (int) (mEvaluator.getMaxIndex() - position + 1);
}
}
private boolean shouldShowHeader(int position, HistoryItem item) {
if (position == getItemCount() - 1) {
// First/oldest element should always show the header.
return true;
}
final HistoryItem prevItem = getItem(position + 1);
// We need to use Calendars to determine this because of Daylight Savings.
mCalendar.setTimeInMillis(item.getTimeInMillis());
final int year = mCalendar.get(Calendar.YEAR);
final int day = mCalendar.get(Calendar.DAY_OF_YEAR);
mCalendar.setTimeInMillis(prevItem.getTimeInMillis());
final int prevYear = mCalendar.get(Calendar.YEAR);
final int prevDay = mCalendar.get(Calendar.DAY_OF_YEAR);
return year != prevYear || day != prevDay;
}
/**
* Gets the HistoryItem from mDataSet, lazy-filling the dataSet if necessary.
*/
private HistoryItem getItem(int position) {
HistoryItem item = mDataSet.get(position);
// Lazy-fill the data set.
if (item == null) {
final int evaluatorIndex = getEvaluatorIndex(position);
item = new HistoryItem(evaluatorIndex,
mEvaluator.getTimeStamp(evaluatorIndex),
mEvaluator.getExprAsSpannable(evaluatorIndex));
mDataSet.set(position, item);
}
return item;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView mDate;
private AlignedTextView mFormula;
private CalculatorResult mResult;
private View mDivider;
public ViewHolder(View v, int viewType) {
super(v);
if (viewType == EMPTY_VIEW_TYPE) {
return;
}
mDate = (TextView) v.findViewById(R.id.history_date);
mFormula = (AlignedTextView) v.findViewById(R.id.history_formula);
mResult = (CalculatorResult) v.findViewById(R.id.history_result);
mDivider = v.findViewById(R.id.history_divider);
}
public AlignedTextView getFormula() {
return mFormula;
}
public CalculatorResult getResult() {
return mResult;
}
public TextView getDate() {
return mDate;
}
public View getDivider() {
return mDivider;
}
}
}
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